Enhanced Visible‐Light‐Driven Photocatalytic Overall Splitting of Pure Water in a Porous Microreactor

Photocatalytic overall splitting of pure water (H₂O) without sacrificial reagent to hydrogen (H₂) and oxygen (O₂) holds a great potential for achieving carbon neutrality. Herein, by anchoring cobalt sulfide (Co₉S₈) as cocatalyst and cadmium sulfide (CdS) as light absorber to channel wall of a porous polymer microreactor (PP12), continuous violent H₂ and O₂ bubbling productions from photocatalytic overall splitting of pure H₂O without sacrificial reagent is achieved, with H₂ and O₂ production rates as high as 4.41 and 2.20 mmol h^-1 g_cat. ^-1 respectively. These are significantly enhanced than those in the widely used stirred tank-type reactor in which no O₂ is produced and H₂ production rate is only 0.004 mmol h^-1 g_cat. ^-1. Besides improved charge separation and interaction of H₂O with photocatalyst in PP12, bonding interaction of Co₉S₈ with PP12 creates abundant catalytic active sites for simultaneous productions of H₂ and O₂, thus leading to the significantly enhanced H₂ and O₂ bubbling productions in PP12. This offers a new strategy to enhance photocatalytic overall splitting of pure H₂O without sacrificial reagent.